How do you say no in cat language?

There is no special feline word that reliably means no. Hissing, shouting or frightening a cat may stop it momentarily but can also damage trust and fail to explain what you want it to do instead. Identify the need behind the behaviour, then change the setup and reward a suitable alternative. If the cat scratches a chair, for example, offer an appealing scratching surface in a useful location rather than only scolding it. If it reaches an unsafe area, manage access so repeated rehearsal is less likely.

Keep your responses consistent and avoid punishment after the event, which the cat may not connect with the earlier action. Persistent problems can have environmental or health causes. Ask your vet or a qualified behaviour professional for help when simple changes are not enough. Make the alternative easy to choose: a scratcher hidden across the room is less practical than an appealing surface beside the furniture being scratched.